1. Field of the Invention
This invention relates to a tape cassette which contains a tape-shaped recording medium to be used by a recording and reproducing apparatus for recording or reproducing image or sound information by means of a rotary head drum which is provided with a head or heads.
2. Description of the Related Art
Reduction in sizes of camera-integrated type video tape recorders or the like has made rapid progress of late. However, the size of the tape cassette and the diameter of the rotary head drum are laying limits to the possible reduction in size of the mechanism of a video tape recorder (hereinafter referred to as the VTR).
Therefore, in the case of the VTR of the kind adopting the VHS system, a compact tape cassette which is arranged for short-time recording and is called "VHS-C" is developed so as to reduce the size of the mechanism with the reduced size of the tape cassette. The compact tape cassette VHS-C is arranged to require the use of a cassette adapter. The arrangement, however, presents the following problems:
(1) In loading the compact tape cassette on a VTR arranged for a standard cassette, it is necessary to use the cassette adapter which is expensive. The user of the VTR is required to purchase the cassette adapter and is forced to do the troublesome work of inserting and taking the compact tape cassette into and out of the cassette adapter.
(2) In attaching the compact tape cassette to the cassette adapter, the structural arrangement of a front lid of the compact tape cassette is greatly restricted and is not provided with a locking mechanism for the front lid. This is because the compact tape cassette is not allowed to protrude from the cassette adapter with the front lid thereof left in an open state.
As to a reduction in size of a VTR of the 8 mm type, Japanese Laid-Open Patent Application No. SHO 60-171684 has disclosed an arrangement which is as follows: FIG. 2 of the accompanying drawings is an oblique view showing the reverse side appearance of a short-time recording cassette 30 to be used by the VTR. The short-time recording cassette 30 is arranged to have a wider aperture part 39 on its bottom side 30' than the aperture part 5 of a standard cassette 1 which is shown in FIG. 1, while the outside dimensions of the cassette 30 are the same as the standard cassette 1. To make the aperture part 39 wider, the flange diameters of reels 31 and 32 are reduced by shortening the recordable time of the tape-shaped recording medium. The aperture part 39 is thus widened to allow the mechanism of the VTR to be placed within the outside dimensions of the cassette.
The above-stated arrangement eliminates the shortcomings of the method of using the cassette adapter. However, this arrangement has the following shortcomings:
(1) In order to attain the advantageous effect of the arrangement, the mechanism, particularly the rotary head drum, must be arranged to enter the tape cassette at a position below the upper end of the cassette. This requirement then causes the thickness of the mechanism to increase as a whole. Further, the arrangement limits the latitude of a tape path and also tends to result in a complex mechanism.
(2) The short-time recording cassette has about the same outside shape as the standard cassette. Therefore, the user tends to mistake the former for the latter. To prevent the mistake, the VTR must be arranged to have different loading positions for both the standard cassette and the short-time recording cassette.
As described by way of example in the foregoing, the prior art arrangements for reducing the size of the tape cassette have been hardly satisfactory.